Synthetic polymeric hydrocarbon compositions stabilized with an arylmethylene ether of dialkylphenol compound



United States Patent SYNTHETIC POLYMERIC HYDROCARBON COM- PQSITIONS STABILIZED WITH AN ARYLMETH- YLENE EITHER OF DHALKYLPHENOL COM- PGUND Harold A. Green, Havertown, Pa, assignor to Air Prodnets and Chemicals, Inc., Philadelphia, 1%., a corporation of Delaware N0 Drawing. Filed Mar. 19, 1962, Ser. No. 180,859

7 Claims. ((Il. 260-4535) The present invention relates to substituted phenol compounds and their use as stabilizing agents in polymeric plastics, particularly in polyolefins.

I have found that compounds of the general formula exhibit stabilizing activity for polyolefin fibers and films and/ or for other polymeric plastics, in improving resistance of such plastic materials to actinic and thermal degradation or discoloration. In the above formula R is H,

-CHz- R; I

R is H, or

one of the components R and R containing an arylmethyl radical;

R and R are 'acylic hydrocarbon substituents of 4 to 18 carbon atoms; and

R is hydrogen or an acyclic hydrocarbon radical of 4 to 18 carbon atoms.

Among the compounds falling within the above formulation which have been found particularly eifective for the described purpose, there are included:

la- C (on.

A} (CHM 2,4-di-t-butyl-6-benzy1 phenol J3 (CH3):

Benzyl ether of 2,4-di-t-buty1 phenol 3,l3,52d Patented July 6, 1965 "Ice i: on

( (III).

a Naphtha1y1 ether of 2,4-di-t-butyl phenol aHw Dodecyl benzyl ether of di-nonyl phenol iz zs Dodecyl benzyl ether of dit-butyl phenol C(CH) as (V) Certain of the above compounds have not previously been prepared or described.

:The stabilizers of the invention can be used not only in polyolefin compositions and products, such as polypropylenes and polyethylenes, but also in other plastic compositions subject to degradation by heat and/or light, such as polystyrene and polyvinyl types of resins.

Example I Stabilizer: hours None 20-40 1% compound I 200 1% compound II 170 In addition to the high degree of effectiveness demonstrated for the above compounds, it was also observed that neither of the tested phenolic compounds imparted color to the polymer on exposure. Color formation has been a serious defect of a number of proposed commercial additives.

The benzylether compounds (II) can be prepared in accordance with the methods described in US, Patents 2,109,457, and 2,109,514. Our preferred method involves reaction of equimolar quantities of the alkali metal phenolate with benzyl chloride in glycol ether type solvent.

Example [I The 6-benzyl phenol (I) was prepared by dissolving 206 parts by weight of 2,4-di-t-butyl phenol in chloroform (1 mol per liter of solvent). To the solution there was (added 60 parts by weight powdered anhydrous zinc chlostoichiometric excess of benzyl chloride.

The reaction mixture was refluxed for 40 hours then cooled and washed with water to remove ZnCl The organic layer 'was dried over magnesium sulfate, stripped of chloroform, and fractionally distilled to obtain the 2,4 di-t-bu-tyl-o-benzyl phenol. The produetwas recovered as a solid of oil-white color; boiling at 193 C. at 10 mm. Hg abs. and melting at 54 C. The infra red spectrum showed strong phenolic absorption at 2.95 mp.

Calculated Found f! 021E250 Percent G -L- 85' 84.8 Percent H 9. 9. 7

Example III Benzyl ether of 2,4-di-t-butyl phenol (II) was prepared by reacting at 50 C. substantially equimolar quantities of potassium salt of 2,4-di-t-butyl phenol with benzyl chloride in dimethyl ether of ethylene glycol 0/: liter per gram mol of phenolate). After stirring for 24 hours, the solution was filtered to remove KCl and stripped of solvent. The product was isolated by crystallization from ethanol-water, obtaining white needles, M.P. 88 C.

Example IV By the same method described in Example III, above, compound III was prepared by reaction of 2,4-di-t-butyl phenol with 1-chloromethylnaphthalene. The obtained alpha naphthalyl ether of 2,4-di-t butyl phenol is a white solid melting at -95-97 C., the infra-red spectrum showto 150 C. under vacuum (4 mm. Hg). A viscous yellow oil was obtained. The infra-red spectrum showed no band corresponding .to phenolic hydroxyl and strong absorption at 8.10 mg (ether band) Calculated Found for 03311 Percent C 85. 3 Percent H. 11. 2

" Ex ample: VII

Polypropylene was milled respectively with 1% and 2% of dodecyl benzyl ether, of di-nonyl phenol (IV) and extruded to mono-filaments. Another batch of polypropylene was milled with compound (V). These were exposed under tension to Fade-O-Meter test with the results shown below and compared with other phenolic stabilizers.

ing strong absorption at 8.1 m (ether) and being devoid 1 of absorption at 2.95 m (phenolic hyd-roxyl).

Calculated Found Percent C 86. 7 86. Percent H 8. 7 I 8 This compound as well'as the corresponding benzyl ether (II) were found to exhibit stabilizing activity for impact polystyrenes. Y

a Example V I I 7 Compound IV was similarly prepared. The sodium salt of di-nonyl phenol was dissolved ind-imethyle-ther of ethylene glycol to provide a solution containing approximately '1. mol of saltper liter of solvent. qThe solution was heated to reflux and a slight molar excess (1.1/1.0)

' of dodecyl benzyl chloride added. The dodecyl ether of di-nonyl phenol was obtained as an oil-white viscous liquid.

Calculated Found for 04311720 Percent C 85. 5 84. Percent H 11. 8 10.

The compound is active as a stabilizing agent for polypropylene. Example VI Example VIII 1% each of compounds I and III, respectively, were incorporated into a commercial sample of impact polystyrene (Dow 475-B) by preheating for three minutes and milling at 275 F. The milled stocks were molded into 4 slabs under the following conditions in an eight minute cycle:

5 /2 min., contact pressure 375 F. 1 /2 min., 30,000 p.s.i.v 375 F. a 1 min., 35,000 psi Cold press.

The samples were tested under standard conditions (ASTM-D638) and found to show a marked retardation of embrittle'rnent of milled and molded product, as follows:

Stabilizer Compound I I III None Unmilled, unmolded:

Yield strength, p.s.i 3, 060 Breaking strength, p.s.i 2, 410 Ultimate elongation, percent 42 Milled and molded:

Yield strength, p.s.i 3, 960 3, 855 3, 940 Breaking strength, p.s.i 2, 735 2, 750 2, 890 Ultimate elongation, percent 18 34 7 To prepare the d-odecyl benzyl ether of 2,4-di-t-butyl phenol (V), 1 14 parts by weight of the sodium salt of 2,4-di-t-butyl phenol were dissolved in ethylene glycol dimethyl ether to provide a solution having 228 parts phenolate per liter of solvent. To the obtained solution 7 7 there was added 146 parts by weight of dodecyl benzyl chloride and the mixture stirred at 35 C. for 48 hours.

'The'solvent was distilledoff until pot temperature rose to 100 C., and the residue refluxed with imeth-anolic sodium hydroxide (Olaisens alkali), with addition of hen,- zene to facilitate separation of the layers. The product layer was washed with water until free of chloride, and

Compound II gave results similar to compound I above.

In general the phenolic stabilizing agents should be employed in quantities of from about 0.1% to 2.0% by weight of the resin polymer. For example, about 0.5% of compounds I or III would be suitable for stabilization of low density polyethylene, while for polyvinyl chloride as little as 0.1%- may be used. Auxiliary stabilizers may be included to provide extended oven life in the presence of atmospheric oxygen. 7

Obviously many modifications and variations of the invention as hereinbefore set forth may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims.

What is claimed is:

1. The method of stabilizing synthetic polymeric hydocarbon materials to improve their resistance to actinic and thermal degradation which comprises the incorpora-.

tion therein of from 0.1% to about 2% by weight of a stabilizer which is an arylmethylene ether of dialkylphenol in which each alkyl gorup contains from 4 to 18 carbon atoms.

2. The method of stabilizing synthetic polymeric hydrocarbon materials to improve their resistance to actinic and thermal degradation which comprises the incorporation therein by milling at a temperature of from about 450 F. to about 500 F. from 0.1% to about 2% by weight of dodecyl benzyl ether of di-nonyl phenol.

3. Stabilized polymeric hydrocarbon plastic composition containing from 0.1% to about 2% by weight of dodecyl benzyl ether of di-nonyl phenol.

4. Stabilized polymeric hydrocarbon plastic composition containing from 0.1% to about 2% by weight of alpha naphthalyl ether of 2,4-di-t-buty1 phenol as stabi1izing agent.

5. Stabilized polymeric hydrocarbon plastic composition containing from 0.1% to about 2% by weight of benzyl ether of 2,4-di-t-butyl phenol as stabilizing agent.

6. Impact polystyrene stabilized with from 0.1% to about 2% by Weight of benzyl ether of 2,4-di-t-butyl phenol.

7. Impact polystyrene stabilized with from 0.1% to about 2% by weight of alpha-naphthalyl ether of 2,4-dit-butyl phenol.

References Cited by the Examiner UNITED STATES PATENTS 2,181,119 11/39 Caplan 260-612 2,213,218 9/40 Hester 260-612 2,276,117 3/42 Taylor et al. 260619 2,789,108 4/57 Mills et al. 260-4595 2,909,504 10/59 Spacht 26045.95 3,047,503 7/62 Jaffe et .al 260-4595 3,134,751 5/ 64 Costello 260-4595 3,134,752 5/64 Costello et a1 260-4595 JOSEPH L. SCHOFE, Primary Examiner.

I. R. LIBERMAN, DONALD E. CZAIA, Examiners.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,193,526 July 6, 1965 Harold A. Green It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 45, for "acylic" read acyclic column 4, in the first table, under the column heading "Found" insert the following:

column 5, line 3, for "gorup" read group Signed and sealed this 15th day of February 1966.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. THE METHOD OF STABILIZING SYNTHETIC POLYMERIC HYDROCARBON MATERIALS TO IMPROVE THEIR RESISTANCE TO ACTINIC AND THERMAL DEGRADATION WHICH COMPRISES THE INCORPORATION THERE OF FROM 0.1% TO ABOUT 2% BY WEIGHT OF A STABILIZER WHICH IS AN ARYLMETHYLENE ETHER OF DIALKYLPHENOL IN SHICH EACH ALKYL GROUP CONTAINS FROM 4 TO 18 CARBON ATOMS. 